Blender 2.8. Render to video file with audio from Video Editing section
Render operator is located in top row of app Render > Render Animation (Ctrl+F12).



Check if under Output Properties > Post Processing > Sequencer is enabled.



If it is not the case attach simplified blend only with a short sample of movie, so we can check. But if you are able to render with different codec I'm not able to help since issue lies somewere in your PC condition.